Caring for a Three Legged Dog or Cat
Tripawds is your home to learn how to care for a three legged dog or cat, with answers about dog leg amputation, and cat amputation recovery from many years of member experiences.
Last November we had a live chat with board-certified veterinary oncologist Dr. Michael Lucroy. During the chat, a member asked him about a canine cancer study which concluded that removing the primary cancer site will actually make cancer metastasize faster.
The member wondered if we do amputate, aren't we still in a no-win situation?
At the time, Dr. Lucroy didn't have the study on hand, so we followed up with him recently and here's what he said:
"I think your member is thinking about a study done several years ago (Pirie-Shepherd SR, Coffman KT, Resnick D, et al. The role of angiostatin in the spontaneous bone and prostate cancers of pet dogs. Biochem Biophys Res Commun 2002 292(4):886-91.) as a collaboration between researchers in Boston and Purdue University.
The researchers were studying angiostatin, which is a potent inhibitor of angiogenesis (development of new blood vessels). Because cancer requires nutrition to grow, it must recruit the growth of new blood vessels in order to grow beyond a handful of cells. The researchers discovered that the urine of dogs with osteosarcoma contained angiostatin fragments. Once the primary tumor was completely removed (by amputation) the angiostatin fragments were no longer detectable.
The theory is the primary tumor keeps the metastases in check. Clinically, we observe that very few dogs have metastasis visible on chest x-rays at the time of diagnosis, but if we we examine lung tissue there are osteosarcoma cells detectable under the microscope. After amputation, if nothing else is done, these micrometastases start to develop quickly. The results of this study provide the biological mechanism to explain our clinical observations.
But it is important to note that although we cannot see them with chest x-rays, microscopically the metastatic event has already occurred. So removing the primary tumor does not cause the cancer to metastasize faster, but simply allows the metastatic sites already present to start to grow.
Occasionally we have dog owners who are aware of this research and suggest we simply leave the bone tumor in place. Ethically, however, we cannot do this if we want to relieve suffering. Bone cancer is very painful, and we cannot easily control chronic pain.Therefore we are obligated to either amputate the affected leg or treat the tumor with radiation therapy and pamidronate to relieve the pain.
We now know that by doing this, we are removing the source of angiostatin – which inhibit the growth of the micrometastases. So, enter chemotherapy to slow the growth of these metastatic sites."
Many thanks to Dr. Lucroy for taking the time to answer this valid question.
20 May 2009
So, I have been thinking and wondering about this. What if before amputation we did two rounds of chemo with four more after the amputation. Does that seem like it would help with life expectancy?
My lab, Bentley, just started limping and because of our experience with Emily I am understandably nervous. If he is still limping tuesday when she is back in her office we will take him in.
Does there seem to be any validity to my thinking?
Debra, Emily's Mom who does NOT want to start posting as Bentley's Mom
Debra & Emily, a five year old doberman mix, who was diagnosed with an osteosaecoma. She had a right rear leg amputation on May 19, 2009. On November 10, 2009 she earned her wings and regained her fourth leg.
26 November 2008
The initial Admin posting is pretty much what I was told by my oncologist. At the time of Miss Cherry's diagnosis, the "latest" was to start the chemotherapy as soon as the body returned to normal temperatures after the amputation. Thus, Miss Cherry's fist chemotherapy was administered just hours after completion of the amputation. The idea is to attack the remaining cancer cells that are suspended in the blood before they have a chance to find another host area. I mentioned for the first time in January, that Miss Cherry actually had another growth on her kidney at the time of the initial diagnosis. An attempt at needle biopsy and aspiration during the initial visit with the oncology and surgical team was not successful. That growth did "burst" dumping significant amounts of blood into Miss Cherry's urine approximately 6 weeks after the amputation. However, since I did not want to subject her to exploratory surgery, we will never know if this was a cyst, a tumor different from the osteosarcoma, or if the osteosarcoma had already metastasised onto her kidney. While I can not remember exactly whom, I distinctly remember one of our community where they actually preformed chemotherapy before the amputation. Also, many women are having chemotherapy prior to operating on breast cancer.
With this additional growth on her sole functioning kidney, you can see that Miss Cherry's initial prognosis was not very good. I never did discuss with any of our team the dreded "Life Expectency". We just ignored that issue and "just went for it!" To me, this just makes her 405 days as a TriPawd even more remarkable, and perhaps proves the wisdom of starting her chemotherapy so early. Either way, I loved every second of the time, and nearly every second of the time was spent with a very high quality of life. After all, that is what it was all about.
Oh Debra, we hope that Bentley is OK. I know what you mean about being nervous. Whenever our Wyatt Ray starts slowing down or acting like he doesn't want to walk, we hestiate for a minute, and try not to think about the worst case scenario. We never want to go there again.
Hope it's nothing. Keep us posted OK?
Bob, your experience with Cherry and chemo was one of the first times we had heard about giving chemo immediately after surgery. We're so glad you're here to share that with us all. Thank you.
7 February 2010